Nowadays, the amount of e-waste generated globally is growing at a faster speed, due to consumers' repetitive consumption and product replacement stimulated by electronics manufacturers. This leads to severe threats to our environment. However, a large amount of e-waste is not waste at all. They could be well refurbished and then reused by the next owner because most are obsoleted before their fully functional lifetime. In addition, many consumers are willing to purchase those pre-owned electronic devices beyond their up-to-date time. Therefore, Valyuu, a Dutch-based circular electronics start-up, is one of the retailers that work in this field. Valyuu is currently seeking to grow its seller market, by attracting more customers to sell their EOU devices to it. However, there is a big challenge that most consumers are not managing their EOU devices properly but simply storing them at home. In order to solve this challenge and achieve Valyuu’s seller market growth, the research questions were derived, and this project was initiated. Firstly, the context analysis was conducted to understand the contextual elements that influence consumers’ behaviors. Then, Valyuu’s competitive environment in its related market field was briefly scanned. At the same time, the literature review formulated a theoretical foundation to progress this project further. Afterward, instructed by the conclusions from the literature, consumer research was conducted, which is the core activity in the research phase of this project. After that, all of the conclusions in the first 5 Chapters were integrated and taken into consideration when assessing and selecting the target group, lazy ignorers, and forming the design brief. Till then, the research phase was wrapped up and the ideation phase started. After conducting the co-creation workshop, the design opportunities and guidelines were specifically proposed, which instructed the development of initial concepts. Next, after evaluating the initial concepts and combining the well-performed properties of selected initial concepts, the final concept was delivered. It is basically an influencer marketing promotion scheme, aligned with the launching of the door-to-door pick-up service, including an influencer’s video and Valyuu’s promotion web pages. Finally, the final concept was validated by both the target group and Valyuu’s co-founders, which proved its feasibility, desirability, and viability. After that, a roadmap for Valyuu to further grow its seller market with expansion into other segments was briefly proposed. In the end, some recommendations for further studies were given.